Butt welding flange connection and construction requirements

　　In pipeline engineering, it is very common to use flange connection between pipelines. When connecting important or relatively more important and expensive pipelines, butt welding flange is usually selected, because the process of butt welding flange is complex and the cost is relatively high, Performance is better than the general flange, used in key parts more appropriate.

　　There are some problems in adopting the construction method of repeatedly welding the head at the ball receiving place: first, increasing the labor intensity of workers; The second is the high consumables, large-scale equipment and high cost. In order to solve the problems of high labor intensity, high consumables, many times of large equipment required and high cost when using the method of repeated welding head at the service point when sweeping the line through the ball after the pressure test of long-distance pipeline, a new simple quick opening flat welding flange construction method is proposed. Flat welding flange is suitable for steel pipe connection with nominal pressure less than 2.5MPa. The sealing surface of flat welding flange can be made into smooth type, concave convex type and tenon groove type. Smooth flat welding flange is the most widely used, and the other two kinds of butt welding flange are also common in use. Flat welding flange has a wide range of uses. The range of use is determined according to different characteristics. It is mostly used under mild medium conditions, such as low-pressure non purified compressed air and low-pressure circulating water. Its advantage is that the price is relatively cheap.

　　With the rapid development of the domestic and foreign pipeline construction, the pressure test of butt welding flange becomes an indispensable important link. Before and after the pressure test, it is necessary to carry out the ball sweeping for each section of pipeline, the number of times is generally 4 ~ 5. Especially after the pressure test, it is difficult to clean the water in the pipeline, and the cleaning times will be more. Flat welding flange is a kind of flange, which is widely used and promoted in the mechanical industry, and has been praised and favored by users. The main application environment of flat welding flange is suitable, which needs to be determined according to the specific situation. Hebei Flange Factory guarantees the specific use value and performance of flat welding flange. It is one of the butt welding flange, which is widely used and promoted in the mechanical industry, and has won the praise and favor of users. Flange manufacturing is simple, low cost, but the welding workload is large, electrode consumption is large, can not withstand high temperature, high pressure, repeated bending and temperature fluctuations, generally used for PN ≤ 2.5MPa, normal temperature, working temperature T ≤ 0 ℃. The other is to weld the outer weld between the flange and the pipe, as well as the inserted flange of the pipe. The pipe and the flange surface should be welded according to the assembly requirements of the drawing. Note that the flange surface should not be damaged or the sealing is not good. The welding method is manual arc welding, and the welding according to the welding process requirements can be used.